Featured Research

from universities, journals, and other organizations

Magnetic nanowires: Domain walls as new information storage medium

Date:

September 23, 2013

Source:

Universität Mainz

Summary:

While searching for ever smaller devices that can be used as data storage systems and novel sensors, physicists have directly observed magnetization dynamics processes in magnetic nanowires and thus paved the way for further research in the field of nanomagnetism. Small magnetic domain wall structures in nanowires can be used to store information and, for example, can be used as angle sensors. Initial applications based on magnetic domain walls have been developed and are already in use in sensor technology.

While searching for ever smaller devices that can be used as data storage systems and novel sensors, physicists at Johannes Gutenberg University Mainz (JGU) have directly observed magnetization dynamics processes in magnetic nanowires and thus paved the way for further research in the field of nanomagnetism. Small magnetic domain wall structures in nanowires can be used to store information and, for example, can be used as angle sensors. Initial applications based on magnetic domain walls have been developed and are already in use in sensor technology.

Related Articles

The current findings represent the first experimentally recorded direct imaging of predicted correlations between magnetic spin structure and wall velocity. The newly discovered properties could be used for other future applications in information technology.

Magnetic domains represent regions of uniform magnetization in ferromagnetic materials. Within each domain, the magnetization is aligned in a single direction. At the interface where domains of different magnetization direction meet, the magnetization has to rotate from one direction to another in a so-called domain wall. At Mainz University, the group of Professor Mathias Kläui is studying the properties of magnetic domains and the dynamics of domains and domain walls in tiny rings on the nanoscale. It is possible to directly observe the motion of domain walls in these rings that have a diameter of some 4 micrometers and are made of permalloy, a soft nickel-iron alloy. For this purpose, the Mainz physicists have been collaborating with scientists of the BESSY II synchrotron facility at the Helmholtz Center Berlin for Materials and Energy and the Advanced Light Source (ALS) at the Lawrence Berkeley National Laboratory, Berkeley, USA, as well as with the Technical University of Berlin and the Max Planck Institute for Intelligent Systems in Stuttgart.

The researchers discovered that the velocity of the motion of domain walls is always oscillating. "This is a new effect that could prove to be useful in the future," said Dr. André Bisig, lead author of the paper "Correlation between spin structure oscillations and domain wall velocities," which has recently been published in Nature Communications. It was also found that the applied method is very effective in reliably moving the domain walls at very high velocities. "The faster we move the domain wall, the easier it is to control it," said Bisig. Another observation concerns the effects associated with irregularities or defects in the nanowires. According to the results, these effects only become noticeable when domain walls are moving slowly. The faster a domain wall spins, the less relevant is the role played by defects in the material.

While theoretical research concerns itself principally with observing domain wall velocity and its correlation with oscillations in the spin structure, the results obtained also have important implications for applied research. Domain wall-based sensors are already being used by Sensitec GmbH, Mainz, a cooperating partner of JGU and the Technical University of Kaiserslautern in two projects funded by the state of Rhineland-Palatinate: the Spintronics Technology Platform in Rhineland-Palatinate (STeP) and the Technology Transfer Service Center for New Materials (TT-DINEMA). "Of particular importance is the fact that we observed unimpeded domain wall motion at high domain wall velocities. This represents highly promising potential for the use of these nanostructures in ultra-fast rotating sensors," added Professor Mathias Kläui. The research being undertaken by Professor Kläui's team is being funded by an ERC Starting Grant and the Graduate School of Excellence Materials Science in Mainz (MAINZ). In addition, cooperation with Sensitec has resulted in access to a joint EU project involving seven other leading partners expected to start in October 2013 on "Controlling domain wall dynamics for functional devices."

More From ScienceDaily

More Matter & Energy News

Featured Research

Mar. 31, 2015 — Researchers have recorded the first direct observations of the micro-scale mechanisms behind the ability of skin to resist tearing. The results could be applied to the improvement of artificial skin, ... full story

Mar. 31, 2015 — A year ago, researchers showed that their software endowed the walking robot Hector with a simple form of consciousness. Their new research goes one step further: they have now developed a software ... full story

Mar. 31, 2015 — Landfills can make a profit from all their rotting waste and a new patent explains exactly how to make the most out of the stinky garbage sites. Decomposing trash produces methane, a landfill gas ... full story

Mar. 31, 2015 — Scientists have achieved an unprecedented level of control over defects in liquid crystals that can be engineered for applications in liquid matter photonics. Sitting with a joystick in the comfort ... full story

Mar. 30, 2015 — Neuroscientists are taking inspiration from natural motor control to design new prosthetic devices that can better replace limb function. Researchers have tested a range of brain-controlled devices ... full story

Mar. 30, 2015 — Speaking in public is the top fear for many people. Now, researchers have developed an intelligent user interface for 'smart glasses' that gives real-time feedback to the speaker on volume modulation ... full story

Mar. 30, 2015 — By studying the morphology and physiology of plants with tiny conical "hairs" or microfibers on the surface of their leaves, such as tomatoes, balsam pears and the flowers Berkheya purpea and Lychnis ... full story

Mar. 30, 2015 — In the first study of its kind, scientists quantitatively show that electric vehicles will meet the daily travel needs of drivers longer than commonly assumed. They found that batteries that have ... full story

Mar. 30, 2015 — One researcher has developed a clever solution to gather naturalistic driving data. For several years, she has been using a detailed driving simulator to study how participants respond to ... full story

Bionic Ants Could Be Tomorrow's Factory Workers

Reuters - Innovations Video Online (Mar. 30, 2015) — Industrious 3D printed bionic ants working together could toil in the factories of the future, says German technology company Festo. The robotic insects cooperate and coordinate their actions and movements to achieve a common aim. Amy Pollock reports.
Video provided by Reuters

Related Stories

Apr. 8, 2014 — Researchers have achieved a major breakthrough in the development of methods of information processing in nanomagnets. Using a new trick, they have been able to induce synchronous motion of the ... full story

Oct. 5, 2012 — Researchers have found a surprising effect that leads in ferromagnetic materials to a spatially varying magnetization manipulation on an ultrafast timescale. This effect could be the key to further ... full story

Nov. 23, 2010 — Although they exist in almost every magnetic material, you cannot see them: magnetic domains are microscopically small regions of uniform magnetization. Scientists have now developed a method by ... full story

Aug. 10, 2010 — Just as the path of photons of light can be directed by a mirror, atoms possessing a magnetic moment can be controlled using a magnetic mirror. New research investigates the feasibility of using ... full story

June 9, 2010 — Researchers have found that flaws in the structure of magnetic nanoscale wires play an important role in determining the operating speed of novel devices using such nanowires to store and process ... full story

ScienceDaily features breaking news and videos about the latest discoveries in health, technology, the environment, and more -- from major news services and leading universities, scientific journals, and research organizations.